Delta climate

Delta Weather in May

NOAA 1991-2020 normals for Conowingo Dam, 15.2 km from Delta

Average highs run from 70°F on May 1 to 78°F on May 31, and lows from 49°F to 59°F. Normal precipitation for the month is 3.86 in over about 11 wet days.

May day by day

The normal high and low for each date, and the record, in °F.

Normal daily high and low temperature at Delta, in °F, with the record for each date.20406080100151015202530
  • Normal low
  • Normal high
  • Record high
  • Record low

May at a glance

Average high
74°F
Average low
54°F
Precipitation
3.86 in
Record high
99°FMay 16, 1991
Record low
29°FMay 1, 1978
Chance of a freeze
0%
Days of 90°F or more
1.5
Daylight
13 h 54 min to 14 h 47 min
Cloud cover
63%
Humidity
78%
Dew point
54°F
Wind
7.6 mph

Every day of the month

A wet day has at least 0.01 inch of precipitation; snow means at least 0.1 inch of snowfall.

DateNormal highNormal lowRecord highRecord lowChance wetChance of snow
May 170°F49°F86°F 200729°F 197835%
May 270°F49°F84°F 201033°F 200535%
May 370°F50°F90°F 202434°F 198635%
May 471°F50°F90°F 196531°F 198935%
May 571°F50°F88°F 195531°F 197335%
May 671°F51°F91°F 198636°F 198135%
May 771°F51°F90°F 195932°F 198135%
May 872°F51°F96°F 200031°F 194735%
May 972°F52°F94°F 200030°F 194735%
May 1072°F52°F95°F 200031°F 194735%0%
May 1172°F52°F90°F 197931°F 196635%0%
May 1273°F53°F92°F 195936°F 196334%0%
May 1373°F53°F89°F 199136°F 196734%0%
May 1473°F53°F92°F 195635°F 201334%0%
May 1573°F54°F93°F 199136°F 193934%0%
May 1673°F54°F99°F 199138°F 197334%0%
May 1774°F54°F92°F 197436°F 196734%0%
May 1874°F55°F94°F 196235°F 200533%0%
May 1974°F55°F96°F 199637°F 197333%0%
May 2074°F55°F99°F 199639°F 199133%0%
May 2175°F56°F96°F 199638°F 200233%0%
May 2275°F56°F93°F 193737°F 200233%0%
May 2375°F56°F94°F 196440°F 200232%0%
May 2476°F57°F92°F 196437°F 196332%0%
May 2576°F57°F92°F 199136°F 195632%0%
May 2676°F58°F90°F 196542°F 198832%0%
May 2776°F58°F92°F 199139°F 197232%0%
May 2877°F58°F94°F 199138°F 196132%0%
May 2977°F59°F96°F 199138°F 193632%0%
May 3077°F59°F95°F 199939°F 194932%0%
May 3178°F59°F95°F 200640°F 193831%0%

Chance of rain

The chance of at least 0.01 inch of precipitation on each date at Delta, in percent, and of at least 0.1 inch of snowfall.0102030401102030
  • Chance of a wet day
  • Chance of snowfall

Sunrise and sunset

Times for 2026, local time (EDT).

May 1
sunrise 6:06 AM, sunset 8:00 PM
May 31
sunrise 5:40 AM, sunset 8:27 PM

Every day of May: sun and moon

Other months

Sources

Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00182060 (Conowingo Dam), public domain. Records: NOAA GHCN-Daily, station USC00182060, every year on file, quality-flagged values removed. Cloud, humidity, wind and sunshine: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus.